Inertial and kinematic response of laterally loaded piles: Sensitivity of elastodynamic continuum solutions to key assumptions

This paper discusses the sensitivity of predictions of the inertial and kinematic lateral response of single end-bearing piles to key assumptions of contemporary elastodynamic solutions. This is facilitated by a robust, continuous mathematical model of the dynamic response of the soil-pile system, capable of considering two extreme soil-pile interface scenarios i.e., “smooth” and “rough” boundary, as well as vanishing vertical soil displacements or vanishing vertical normal stresses. The model exploits the theory of confined elastodynamics to accurately quantify soil-pile interaction; the soil surrounding the pile is treated as a Tajimi-type continuum, while the pile is modelled as a one-dimensional elastic Euler-Bernoulli beam. Results of a parametric study with the proposed model demonstrate that the shear boundary conditions at the soil-pile interface have a noteworthy effect on the static and dynamic soil resistance and stiffness of the soil-pile system in the case of inertial loading (lateral loads applied at the pile head). On the contrary, this effect is much less prominent in the case of kinematic loading, associated with propagation of seismic shear waves in the absence of a superstructure. Findings of this study underline the importance of quantifying the effect that simplifying assumptions have on predictions of analytical methods used to model soil-pile interaction when using such methods in research and practice.